Your First Water Garden

By Josh Spece

Water gardening is becoming an ever-popular form of gardening, and it's easy to see why. Who can resist the tranquil scene of colorful fish swimming amongst a beautiful display of water lilies and other marginal flowering and foliage plants with the relaxing sound of running water in the background? At first glance, it may seem that water gardening is too complex or too much work for the average gardener, but that is far from the truth. Once a water garden is set up, it requires less work than a regular ol' dirt garden...no weeds to pull, no wilted plants to water... Now that you're convinced a water garden is for you, here's how to go about creating your own little backyard paradise.

Where do I put my first water garden?

Ideally, your water garden should be in a relatively flat area away from large overhanging trees. The leaves from overhanging trees will fall into your water garden and pollute the water if not removed regularly. The site should receive at least six hours of direct sun every day for the best plant growth and flowering. You should locate your water garden so that it fits in with the rest of your landscape. Also, put it where it can be easily viewed from indoors.

How big does my water garden need to be?

Your water garden can be as large or as small as you want it. The smaller it is, the less time it is going to take for you to take care of it, but it will be able to have a limited number of plants and fish. The larger your water garden is, the wider variety of plants and fish you will be able to have and it really doesnít take that much more time to tend than a smaller one. If you want to leave your plants and fish outdoors all winter (it is recommended that you do) your water garden needs to be at least three feet deep.

Generally, the larger the water garden, the better. It will create a more stable environment for the plants and fish that call it home. A 6' x 10' water garden is a good size to start with. Most people can find a place in their current landscape for a feature this size. No matter how big you make it, once you are bitten by the water garden bug, it will never be big enough!!

How deep should I make my water garden?

If you plan on growing water lilies, your water garden needs to be at least 18" deep. In order to over winter goldfish and hardy water plants in Iowa, it should be at least three feet deep.

Within your water garden, there should be several different depths to accommodate the needs of various plants and animals. A shallow shelf six to ten inches deep should surround the edge of the water garden. This is where marginal plants, frogs, and baby fish will live. Next should be a section 18" to 24" deep for your water lilies and oxygenating plants. Finally, there should be an area at least three feet deep for the fish to and plants to stay during the winter.

How do I keep the water in my water garden?

You have two choices here. You can use a flexible rubber liner or a pre-formed plastic liner. The flexible liners give you the most freedom of shape, size, and depth of your water garden. They are easy to work with, last for at least 10 years, and are readily available. Pre-formed liners come in a limited number of shapes, depths (none of which are deep enough to over winter plants or fish in Iowa), and sizes. They are somewhat more difficult to find and are usually more expensive than a flexible liner of the same size, but may be more durable.

How do I build my water garden?

Buy your liner or preformed pond.

Lay a garden hose in the shape you want your new water garden, so you know exactly where to dig the hole.

Dig the hole.

Make sure the edge of the hole is level all the way around so the water won't run out of a low spot.

Remove any rocks, tree roots, and other sharp objects from the hole.

Line the entire hole with several layers of wet newspaper or old carpet. This will cushion the liner from any sharp objects that may put a hole in it.

The liner is easier to work with if it is warm, so spread it out in the sun for a few minutes. Then lay the liner loosely over the hole, and begin filling it with water.

As the liner is pulled down by the weight of the water, begin folding the excess liner into flat creases.

Cut any excess liner off, and mask it with rocks.

Now your water garden is ready for plants. Wait about a week before adding any fish.

How do I make a waterfall or fountain for my new water garden?

You can mound the soil you removed when digging the hole for the water garden to one side to make a waterfall. Then create a depression where the water will flow back to the pond. Now cover the waterfall with a piece of flexible liner and stack flat stones on it to hide it. The liner from the waterfall should over lap the pond liner to prevent any water from escaping.

To move the water from the pond to the top of the waterfall you will need a submersible pump and a length of hose. You will also need a grounded electrical outlet (GFCI) to plug the pump into. Connect the hose to the outlet of the pump, and place the pump in the bottom of the water garden. Then run the hose to the top of the waterfall. You can hide the hose by burring it or hiding it with rocks or plants. You will probably have to play around with the waterfall to get the water to fall over the rocks just right.

To make a small fountain, all you need is a fountainhead that attaches to the outlet of your pump.

Now am I ready for plants?

Yes, now you are ready to add plants to your water garden. You should try to cover 70% of the water surface with floating leafed plants like water lilies, water lettuce, and water hyacinths. This will shade the water so it doesn't turn green with algae. Water lettuce and water hyacinths grow so fast you will need to thin them out so they donít shade and crowd out other desirable plants like the water lilies.

You will also need submerged plants (anacharis) to help keep the water clean and clear. The rule of thumb here is one bunch per square foot of water surface. These plants also add oxygen to the water for the fish, and provide them a place to lay their eggs.

Large clumps of a few varieties of marginal plants look better than small clumps of many varieties. The more marginal plants you have, the more likely small creatures like frogs will stay around your water garden.

How do I take care of my plants?

Most water plants require very little care. Once they are established, all you need to do is remove dead leaves and fertilize them regularly. You should fertilize all your water plants every two weeks during the summer with special water plant fertilizer tablets or small pieces of tree fertilizer stakes.

What do I do with my water garden during the winter?

After the first hard frost, it is time to put your water garden to rest for the winter. You need to remove as much dead plant material and fallen leaves as possible. If you don't, they will rot in the water over winter and possibly kill your fish. If your water garden is deep enough, just set the hardy plants in the deepest part. Otherwise you will need to keep them wet and cool over the winter, but DO NOT let them freeze!!!

Your tropical plants will need to be removed from your water garden before your first frost. These can be kept wet and cool over the winter, or in a sunny window.

If your water garden is deep enough to over winter hardy plants, goldfish will do fine left out over the winter, too. Koi, on the other hand, do not survive the long, cold winters of Iowa as easily. They will need to be brought indoors and kept in a large aquarium until warmer weather returns, or extra attention will need to be taken to make sure the pond is always open. A partial water change first thing in the spring may also improve their chances of survival. You will need to keep an area free of ice so gas exchange can occur, or else your fish will suffocate. You can do this by leaving your pump running or with a de-icer used for cattle tanks.

Is there anything else I need to know?

Probably, but you will learn a lot from experience! Come to In The Country Garden & Gifts for all your water garden equipment and plants, to ask questions, or tour our garden to get ideas for your own!